The Research And Realization Of Distributed WebGIS Based On J2EE

Geographical Information System(GIS) is developing rapidly all over the world since 1960. GIS reflect the earth space that human society depend on for living, various kinds of space datum and the attributes which describe these datum characteristics. With the rapidly development of internet, world wide web(www or web for short) is becoming the channel of efficiently promulgate of global information. Just in this condition, WebGIS was born, and became one of the important direction of researching on GIS.WebGIS is the combination of GIS technology and network technology, it can simply define as GIS on internet. WebGIS is a new extended technology of GIS by using network technology. WebGIS eliminate the restriction of GIS, it make the function of GIS run on internet. It also make the applied field of GIS from professional system to many fields of society, make GIS become popular tool of information and extend GIS service area infinitely.The development of computer network and Distributed Computing speed WebGIS to the development of Distribution and component. The used centralizing server mode in traditional meaning WebGIS can not meet the need of a large number of information transmissions and a great quantity user accessing simultaneously. In order to realize the geographical information resource in sharing and opening, set up a distributed WebGIS which geographical distributed and integrate logic and also including multi-database servers, GIS application servers and web servers is the developing trend of WebGIS .J2EE is Java 2 Platform Enterprise Edition produced by SUN company which is based on Java, and fit for establishing server application and service. J2EE provides model of multi-layer Distributed application, model of unanimous security and flexible domination of affair. The system based on J2EE has many virtues, such as higher usability, security, extensibility and transplantable. The distributed WebGIS based on J2EE make good use of the platform independent of J2EE system structure, realize a multi-layer , modularization , extensible ,transplantable and platform independent WebGIS application.The thesis focus on "distributed WebGIS based on J2EE". First expound the basic concept of WebGIS > the structure and developing method of WebGIS nowadays.As well as the requirement and advantage of distributed WebGIS .Then research on the main methods of realizing distributed WebGIS based on J2EE and introduce a system structure of distributed WebGIS based on J2EE. Last introduce MapXtreme for Java and use tool of JBuilder to realize a WebGIS based on J2EE.